1993 OBS Speedometer and Cruise Control wiring

[T-Stark]

anyone know how it would be on a 89? and my speedo dosnt work fyi

[88stepside]

anyone know how it would be on a 89? and my speedo dosnt work fyi

1989 trucks have the VSS signal going to the speedometer first, then the signal is "conditioned" and sent to ABS, cruise, and also to original PCM. Once you get your speedo working everything else should work also. Since you have an auto trans with 40 tooth reluctor wheel VSS you can simply run the VSS wires to the speedometer, they should be purple and yellow and they are twisted together. To send the signal from VSS to new ECM just splice into the purple and yellow wire anywhere it is convenient.

To calibrate speedo on 88-90 trucks you will have to do the cluster calibration.

I just went through all this on my truck, but EVERYTHING works now.

[T-Stark]

To calibrate speedo on 88-90 trucks you will have to do the cluster calibration.

how do i do this????? sorry just trying to get all the info i can, or a link so i know what im doing when i start it


Thanks man!

[88stepside]

Check these out:
http://www.fullsizechevy.com/forum/a.../t-155414.html

http://www.chevytalk.org/fusionbb/sh...hp?tid/258562/

Basically, back in the day before DRACs and VSSBs they had the speedo "settings" for tire and gear inside the cluster. The way to change them is not hard once you know how.

I still have the parts in my garage, I'll dig around tommorrow and see if I can find the part numbers.

The second link has a great way to replace factory "clip" with a dipswitch.

[88stepside]

Check these out:
http://www.fullsizechevy.com/forum/a.../t-155414.html

http://www.chevytalk.org/fusionbb/sh...hp?tid/258562/

Basically, back in the day before DRACs and VSSBs they had the speedo "settings" for tire and gear inside the cluster. The way to change them is not hard once you know how.

I still have the parts in my garage, I'll dig around tommorrow and see if I can find the part numbers.

The second link has a great way to replace factory "clip" with a dipswitch.

25085515 and 25084374 are the GM parts we used to use to calibrate 88-90 C1500 speedometers. Hope this helps.

[T-Stark]

Thanks man I'll try and get this working soon I'll pm you if I have any problems

[91blkstpsd]

Any idea if the DBW cruise works the same way by hooking up the DRAC to the speedometer wire like mentioned? I would like cruise in my 93 with 04 5.3L but if not its no big deal..